The present invention relates to a tire forming system for consistently forming a pneumatic tire from materials and a tire forming method using the system and, more detailedly, relates to a tire forming system and a tire forming method, which facilitate a stage switchover of tires different in specification and make it possible to greatly increase a production efficiency of the tire.
In the pneumatic tire, there are many sizes owing to differences in oblate ratio and tread width even if bead inner diameters are the same. Further, even if the tire sizes are the same, there is the fact that kinds of compounds and the like are finely assorted in compliance with use objects.
In case of forming such many and various pneumatic tires, setting conditions of a forming machine for the tire size can be almost automatically changed at present, but a lot of time is required in a stage switchover of members supplied to the forming machine. Therefore, hitherto it is adapted such that the members for every tire size are preliminarily prepared, these members are supplied to a forming process and collected in a lot unit for every tire size to assemble unvulcanized tires. That is, in the tire forming process, by increasing the number of tires in one lot, the stage switchover operation is reduced, so that it becomes possible to increase a productivity.
However, a vulcanizing cycle time consumed for vulcanizing one tire is about 5 to 10 times a forming cycle time consumed for forming one tire, so that a correspondence of one to one has been impossible. Therefore, even if tires of specified size are continuously formed in a lot unit, it is impossible to use metal molds for vulcanizing the tires of specified size in agreement with the forming cycle time and, as a result, the unvulcanized tires stagnate as intermediate goods in process, i.e., a lead time increases, so that the production efficiency has been reduced.
Further, in case where, like the prior art, the members for every tire size are preliminarily prepared and these members are supplied to a forming process, it is indispensable to prepare and stock many intermediate members in compliance with many and various pneumatic tires. Therefore, material expenses and management costs of the intermediate members increase, so that a production cost of the tire has been raised.